In order to enable Debug Mode (Steam version):
Open and edit "settings.lua" with a text editor.
Change "debugMode = false," to "debugMode = true," without quotes.
Typical Steam version on a 64-bit location of settings.lua:
C:\Program Files (x86)\Steam\userdata\[Steam User ID]\446800local
Code - Effect:
ALT+M - Adds 500K of money.
ALT+L - Displays lanes.